350 D. M. Balch on Orthite from Swampscot, Mass. 
of iron and alumina in precipitate a, I digested it, while still 
moist in aqueous oxalic acid; the separation was perfect, and the 
insoluble oxalates obtained were free from iron; after standing 24 
hours, these were well washed, dried, ignited and weighed as 
ceric-oxyd and yttria. The sesquioxyd of iron and the alumina, 
contained as acid oxalates in the filtrate and washings of the 
above, were now separated, in the first case as usual, by po- 
tassa; in the second analysis by evaporating to dryness, igniting 
to destroy oxalic acid and expel ammoniacal salts, peroxydizing 
any reduced iron by nitric acid, and weighing the mixture of 
Al,O,+¥Fe,O, as a control to the first analysis. 
These analyses were performed exactly alike, with the ex- 
A B 
= ee ec. SSRI 32°94 
eae 1473 ~=Al,O : 
Ferrous oxyd, - - - 1582  FesOs kas ” 
Cerousoxyd,-- - + 21-94 20°71 
SOR, cs et ee 1°32 
Lime, = ae te 7°85 787 
Magnesia, - - ‘7-25 1°47 
BGRy oc * + Lao (undetermined) 
\ ica ree 1°49 
97°71 99°40 
In orthite and allanite about half the iron is usually in the 
State of sesquioxyd; in analysis A, all the iron is calculated as 
n 
protoxyd which occasions 
time 
+ Dana’s Mineralogy, 1854, Pp 910. 
